The present invention relates to a fabric position correcting device, and more particularly to a fabric position correcting device for correcting a positional deviation of one or two fabrics from a preset position or a relative position based on a detected position of an outer profile line and/or pattern of the fabric or fabrics.
Heretofore, there have been proposed various fabric position correcting devices for correcting a positional error of one or two fabrics so that the fabric or fabrics are brought into a preset position with respect to an outer profile line of the fabric or fabrics.
For example, Laid-Open Japanese Patent Application Kokai No. 63-164991 discloses a fabric position correcting device having three plates lying substantially horizontally and spaced vertically, and an edge guide positioned in front of a needle plate and supporting a pair of upper and lower abutments disposed between the three plates. Lower and upper fabrics are inserted between a lower side plate and an intermediate plate and between the intermediate plate and an upper side plate, respectively. The lower and upper fabrics are moved by compressed air in a direction normal to a fabric feeding direction until linear side edges of the lower and upper fabrics abut against linear side edges of the respective abutments, so that the positions of the side edges of the fabrics are corrected and a sewing margin is corrected. Thereafter, the fabrics are fed to a preset position in the fabric feeding direction to correct the positions of the leading ends of the fabrics. The fabrics that are aligned in the preset position are simultaneously fed to a predetermined stitching position.
However, the fabric position correcting device disclosed in the Japanese publication No. 63-164991 has the following problems: Since the abutments for correcting the sewing margin are attached to the edge guide, the abutments must be positionally adjusted each time the sewing margin is to be altered. Inasmuch as the positional correction in the direction normal to the fabric feeding direction is effected by the linear side edges of the abutments, the fabrics cannot be positionally corrected accurately with respect to outer profile lines thereof if the side edges of the fabrics are not linear in shape. The fabrics cannot be corrected in position by varying the relative position thereof because the relative position of the upper and lower abutments cannot be varied.
Further, there have been proposed a fabric position correcting devices for correcting a positional error of one or two fabrics so that the fabric or fabrics are brought into a preset position with respect to pattern of the fabric or fabrics.
For example, Japanese Patent Publication No. 2-46708 discloses a fabric pattern aligning device in which a fabric mount table which mounts thereon a fabric is drivingly rotatable and movable in X, Y directions by a fabric position correcting means, and a camera is provided for detecting a striped pattern of the fabric mounted on the table. Inclination angle of the striped pattern is computed based on an image data indicative of the striped pattern imaged through the camera. The table is driven by the fabric position correcting means in accordance with the computed inclination angle, so that the pattern can be directed in a predetermined orientation and can be positioned in a predetermined position, to thereby correct the positional deviation of the fabric. The thus corrected fabric is mounted on a fixing means.
According to the fabric pattern aligning device, displacement angle and position of the striped pattern can be corrected on a basis of the image data obtained by the image through the camera. However, the camera only picks-up the striped pattern on the fabric, and the picked-up portions of the fabrics are not constant with respect to every pick-up operation. Therefore, the position of the fabric held on the fixing means may be displaced in the strip pattern direction and a direction perpendicular thereto by integer times of a pitch of the striped pattern. With such a reason, in an attempt to stitch a pocket cloth to a predetermined position of a front garment with aligning pattern or striped patterns thereof with each other, it would be difficult to accurately correct relative positional deviation or error with respect to an outer profile and pattern of these fabrics.